Zobrazeno 1 - 10
of 53
pro vyhledávání: '"Robin Keir"'
Publikováno v:
Earth and Planetary Science Letters. 270:338-348
Hydrothermal emission of mantle helium appears to be directly related to magma production rate, but other processes can generate methane and hydrogen on mid-ocean ridges. In an on-going effort to characterize these processes in the South Atlantic, th
Publikováno v:
Geochimica et Cosmochimica Acta. 70:5766-5778
Abiogenic methane may be produced in submarine hydrothermal systems by degassing of basalts or serpentinization of ultramafic outcrops. The latter process presumably releases little primordial helium and is therefore implicated by high CH4/3He ratios
Publikováno v:
Deep Sea Research Part I: Oceanographic Research Papers. 52:1043-1070
Previous work has shown that methane anomalies frequently occur within the rift valley of the Mid-Atlantic Ridge (MAR). The plumes appear confined within the high, steep walls of the valley, and it is not known whether methane may escape to the open
Publikováno v:
Deep Sea Research Part II: Topical Studies in Oceanography. 48:3179-3189
Previous work has shown that during early summer, the partial pressure of CO2 (pCO(2)) in surface waters north of about 45 degreesN in the Atlantic exhibits widespread undersaturation. In many areas. this follows after a "spring bloom" of phytoplankt
Publikováno v:
Aquatic Geochemistry. 4:403-427
The methane concentration in the atmosphere andsurface water was surveyed along 58° N acrossthe North Sea. In addition, the vertical methanedistribution in the water column was determined at sixstations along the transect. The methane contents ofthe
Autor:
Jürgen Sültenfuß, Maren Walter, Oliver Schmale, Jens Schneider von Deimling, Sharon L. Walker, Gregor Rehder, Robin Keir
Publikováno v:
Geochemistry, Geophysics, Geosystems. 13
The Logatchev hydrothermal field at 14°45′N on the MAR is characterized by gas plumes that are enriched in methane and helium compared to the oceanic background. We investigated CH4 concentration and δ13C together with δ3He in the water column o
Autor:
Robin Keir, Robert L. Michel
Publikováno v:
Geochimica et Cosmochimica Acta. 57:3563-3573
The process of carbonate dissolution at the sediment-water interface has two possible endmember boundary conditions. Either the carbonate particles dissolve mostly before they are incorporated into the sediment by bioturbation (interface dissolution)
Autor:
Robin Keir
Publikováno v:
Geophysical Research Letters. 37
The concentrations of methane and hydrogen in hydrothermal vent fluids issuing from mid-ocean ridges tend to fall into two groups, one with high concentrations of these gases in ultramafic-hosted vent fields and a second group with relatively lower c
Publikováno v:
Geochemistry, Geophysics, Geosystems. 10
As methane is consumed in the deep sea, its 13C/12C ratio progressively increases because of kinetic isotope fractionation. Many submarine hydrothermal vents emit methane with carbon isotope ratios that are higher than those of background methane in
Autor:
Robin Keir
Publikováno v:
Global Biogeochemical Cycles. 5:351-358
Processes that shift nutrients from mid to lower ocean depths may or may not increase the ocean's vertical carbon pump. Redistribution of δ13C produced by these processes is compared in two box models: a vertical three-box ocean and a thirteen-box o